Seismic sequence in Northern Italy

7.15 p.m. update

Two new seismic shocks were registered this afternoon in Reggio Emilia and Verona provinces, after the ones communicated in the previous update. The first occurred at 2.29 p.m. with a magnitude (Ml) 2.4, whereas the second occurred at 6.43 p.m. with a Ml 3.5.

11.30 a.m. update

On 25 January 2012, at 00:54 a.m., a seismic shock of magnitude (Ml) 4.2 hit the area of  Prealps of Veneto, in the province of Verona. At 09:06 a.m. a shock of magnitude (Ml) 4.9 has affected the Po Valley in the province of Reggio Emilia, at the border with the province of Parma. The two events are not connected.

In Italy each year there are over 10,000 eathquakes, an average of thirty a day, which cannot be predicted. It is thus important to be aware of the danger on the territory and be informed on how buildings where we live, study and work are constructed.

Dangerousness maps and seismic classification show which areas of Italy are affected by a high seismicity, thus where an earthquake is more likely to occur, although the exact time cannot be defined.

Dangerousness maps and seismic classification show which areas of Italy are affected by a high seismicity, thus where an earthquake is more likely to occur, although the exact time cannot be defined. Studies on foreshocks, like the ones ongoing in Northern Italy doesn't allow to assume the occurrence of a stronger shock. As of today, in fact, there are no recognized scientific methods to predict time and place where a quake will occur. The map of seismic dangerousness is still the most effective tool that the scientific community provides for the prevention politics. Prevention is still the best defence from earthquakes and the only wat to reduce any consequence.

On the base of data received from Ingv National Institute of Geophysics and Volcanology and Seismic and volcanic risk Office of the Department of Civil Protection, we publish in depth examination of the phenomena. With the occasion, we present again the test on seismic risk prevention and remind our readers some rules of behaviour.

Seismic sequence in the province of Verona
The Prealps of Veneto are currently affected by a seismic sequence located at about ten kilometers north of Verona. Ten shocks have been registered so far, with magnitude Ml between 1,6 and 4,2; the strongest ones are Ml 2,7 (08:41 p.m. of 24 January), Ml 2,5 (07:15 a.m. of 25 January) and Ml 2,9 (08:26 a.m. of 25 January). The depth of hypocenters was more or less located at ten kilometers underground.
The main shock was perceived in a wide area of Veneto and eastern Lombardia, in particular in the municipalities of Bosco Chiesanuova, Cerro Veronese, Fumane, Grezzana, Marano di Valpolicella, Negrar, San Pietro in Cariano, in the province of Verona.
Veneto is a region seismically active, due either to its own seismogenetic faults and to the ones of nieghbouring regions.
Seismicity is concentrated in various areas, all of them along the Prealps area: Verona province (in the passage between Lessini Mountains and the valley, along Illasi and Chiampo valleys), Treviso province (in particular the area of Asolo) and Belluno province (mainly in the area of Alpago-Cansiglio).
The area affected by the ongoing sequence has a medium-low seismicity, according to the Ingv seimic dangerouness map of Italy. Throughout history, the area had been hit by few quakes, although their magnitude was important: in 1891 the quake of Illasi valley had a magnitude between 5,7 and 5,9 and in 1117 a major earthquake in Verona area probably has a magnitude higher than 6,5. A description of the effects of the main historical quakes is contained in the technical file of Veneto seismicity.
Over the past 10 years the area has been affected by a pretty low instrumental seismicity.
Municipalities affected by the sequence lie in zone 3 (low dangerousness) and zone 2 (medium dangerousness) according to the decision on the Regional Council of Veneto no. 67 of 3 December 2003. Specific regulations need to be applied to the buildings of these areas.

Seismic sequence in the provinces of Reggio Emilia and Parma
A seismic sequence is currently affecting the valley between the provinces of Reggio Emilia and Parma, in an area localized in the municipalities of Brescello, Gattico, Poviglio, Castelnuovo di Sotto, province of Reggio Emilia.
Three shocks have been registered so far, with magnitude Ml between 2,3 and 4,9, in particular Ml 4,9 at 09:06 a.m., Ml 2,3 at 09.24 a.m., Ml 2,3 at 10:02 a.m.. Hypocenters were mainly at 25-30 km underground.
The main shock was perceived in a wide area of northern Italy including Veneto, Lombardia, Emilia Romagna, Piedmont and Liguria. No significant damages were reported. Objects fell into houses and rubble and plasterwork came off from some old buildings.
The territory of Emilia currently affected by the sequence has a medium-low seismic dangerousness, according to the Ingv seimic dangerouness map of Italy. The municipalities of the area are classified, lie in zone 3 (low dangerousness) according to the decision on the Regional Council of Veneto no. 1435 of 21 July 2003. Specific regulations need to be applied to the buildings of these areas.
Earthquakes are frequent in Emilia although they rarely exceed magnitude 6. Parma and Reggio Emilia areas, in particular, had been hit by shocks throughout history that never produced effects over the VII degree of the Mercalli scale. An in-depth examination of the main quakes of the past can be found in the technical file of seimicity in Reggio Emilia and Parma areas.